This application relates to a core for forming cooling passages in an airfoil, wherein the core is formed of ceramic components and refractory metal components.
Gas turbine engines are known and, typically, include a number of airfoils. The airfoils may be utilized as turbine blades, turbine vanes, compressor blades and vanes, and at other locations.
As known, in a gas turbine engine, temperatures can become quite high and, thus, cooling passages may be required within the airfoils. One method of forming the cooling passages is so-called lost core molding. In lost core molding, a core is formed and placed within a mold for forming the airfoil. Metal is injected into the mold and solidifies around the core. The core is then leached away leaving internal cavities within the airfoil.
One type of material utilized for the core is ceramics. Ceramics are useful in that they can be made to taper. However, it is difficult to make ceramics into relatively thin shapes.
Another type of core component is formed of refractory metals. Such materials can be made to be quite thin, however, they are limited in being able to form tapering passages.
It has been proposed to utilize the combination of ceramics and refractory metals, however, this has only been done with the refractory metals extending in an axial direction from the ceramic core materials.